Best Hay For Horses With The Most Protein

Last Updated on January 22, 2022

Horses are natural grazers, and therefore receive the bulk of their nutritional needs through forage. However, horse ownership means a degree of confinement behind fencing, so horses are fed hay. With the vast selection of hay on the market, which hay contains the most protein for horses?

Depending on your horse’s individual needs and supplemental feeding program, you may have several options to choose from. Nutritionists recommend horses consume approximately 1.5%-2% of their body weight in forage per day. If consuming enough hay forage daily, even grass hays may provide adequate protein intake for horses.

Hay is for Horses! Nutritional Content of Forage

Unlike humans, horses’ diets are restricted to seasonal and regional grass growth, accompanied by what we provide. This means the bulk of their nutrition comes from forage. When purchasing hay, sellers or feed stores may offer you “test” results for the hay cutting you are purchasing.

Nutritional Content of Forage

Depending on what the grower had tested, this paperwork can reveal vital information about your horse’s nutritional intake. Typically, horse owners will examine dry matter results for moisture, digestible energy (mega calories), crude protein, acid detergent fiber (ADF), neutral detergent fiber, and sometimes essential minerals, micronutrients, and nonstructural carbohydrates (sugars and starches). Regional soil deficiencies, production methods, and climate restrictions can greatly impact these results.

Importance of Protein in Horses

Although protein intake is frequently associated with performance horses and muscle development, protein helps all horses’ bodily functions. Protein assists in nutrient transport, metabolic regulation, buffers to maintain pH regulation, immune system support, and overall growth and repair.

Fats and carbohydrates are easily turned into energy, whereas protein is more difficult to utilize. In addition, horses do not store protein in their bodies for later use. Even though protein requirements will change depending on age, health, and exertion, too much protein can cause health issues. There is no set recommendation for protein consumption, but most horses maintain well at 8-10%, with some increase for heavily working, lactating, or growing horses.

Best Hay for Horses with the Most Protein

When analyzing hay, you will notice not all regions and climates can grow multiple varieties of hay. Hay choice may be limited due to geographical location unless it is being transported into your area. Legume hays are typically higher in protein, as well as calcium, and contain more digestible nutrients.

Legume Hay

  • Alfalfa is a popular choice for supplemental feeding, due to its high fiber and high crude protein content. However, it provides up to 120% more energy than oat hay, and can “heat up” horses. Approximate crude protein minimum: 16%.

Grass Hay

  • Timothy hay is one of the grass hays with higher protein content, sitting at approximately 10% minimum crude protein. Orchardgrass and Bermuda grass hays are similar to Timothy but have even less protein content. Bermuda contains a crude protein minimum of 8%, while Orchard contains a crude protein minimum of 7%.

Grain Hay

  • Both oat hay and forage hay have higher fiber, but lower protein content. Approximate crude protein minimum: 7%.

Protein Supplements for Horses

  • Manna Pro Cool Omega 40+: Equine Dry Fat and Protein Supplement. Rich in protein, fiber, and Omegas 3 & 6 from flaxseed. It is designed to meet the requirements of peak performance horses.
  • Uckele Tri Amino Supplement:  It helps maintain strong muscles, healthy weight, and supports a healthy top-line with the three most essential amino acids (lysine, methionine, and threonine).

  • AniMed L-Lysine for Horses: Recommended for horses whose diets are low in alfalfa, clover, and soy.

Protein Supplements for Horses

Things to Remember

If you have questions about your hay and the seller does not offer test results, you can send in a sample of the forage to a lab. Good resources for equine nutrition and hay composition include your equine vet and agriculture extension agents. Be sure to share this article with your horse friends!


Can you give a horse too much protein?

Surprisingly, yes. Too much protein can damage the kidneys. The horse's kidney system is designed to filter blood so that waste products are removed from the body. The kidneys function by filtering out waste products and reabsorbing water from the urine. In healthy horses, the kidneys work well enough to keep the water balance within normal limits. The amount of water a horse needs is determined by the horse's size. Small horses need about 2 gallons (8 liters) of water per day; larger horses need about 4 gallons (16 liters) per day. Horses need to drink about 3 cups (80 ml) of water per day for each pound (0.5 kg) of body weight. The water is used to remove waste products and excess salts from the horse's system. The waste products are then eliminated in the urine. 

Which kind of hay has the highest protein and energy?

The energy content of a legume hay is generally higher than that of a grass hay. However, the difference in energy content between grass and legume hays may be quite small. Legume hay contains high amounts of protein, minerals, vitamins and other nutrients which are required for good health. The amount of protein in a hay is usually expressed in terms of % dry matter or % crude protein. The percentage of protein can range from 12-45% in legume hays. Legumes have a higher percentage of protein than grass hays.
Legume hays also contain lower amounts of fermentable carbohydrates, crude fibre and ash than grass hays. Moreover, legumes contain all the essential amino acids needed by horses for growth, maintenance and repair of body tissues.

Which is the highest quality plant protein for horses?

There is no one 'best' protein source for any animal and it all depends on the individual needs of the animal. In general though, the higher the quality of the protein source, the better. High quality protein is essential for the maintenance of good muscle mass and overall health. Which is the highest quality plant protein for horses? For horses, the best quality plant protein would be from a high quality soybean or similar seed meal. The amino acid profile of soybean meal is superior to most other seeds and beans with a protein content of 44-48%. However, the cost of soybean meal is much greater than other protein sources such as canola and sunflower seed meal.

Which hay has most protein?

Alfalfa is a legume that grows in clumps and provides a high-protein diet for livestock. Because it grows in clumps, it needs more time and labor to harvest and chop alfalfa hay than grass hay. It also requires additional drying, which adds expense and makes the finished product more prone to spoilage. 
What are some ways you can use alfalfa in your horse's diet?
You can feed alfalfa hay as a roughage source, but be careful not to overfeed it or else it will have the same effect on your horse's digestive system that eating too many grains does. Alfalfa hay should be fed only as part of a balanced diet. It contains enough fiber to help keep your horse's digestive tract healthy. Also, alfalfa hay is high in protein and minerals, and is an excellent source of calcium. It has a low GI (glycemic index) value, so it causes less blood sugar spikes than other feeds.